Fix error handling as well as add new command

for closing the communication socket. As well as get
error messages back from running instance to client process.

Signed-off-by: Werner Fink <werner@suse.de>

5 files changed, 226 insertions, 84 deletions

diff --git a/man/haveged.8 b/man/haveged.8
index 75bc5a2..edbc611 100644
--- a/man/haveged.8
+++ b/man/haveged.8
@@ -34,7 +34,11 @@ Set collection buffer size to nnn KW. Default is 128KW (or 512KB).
 -c cmd, --command=cmd
 Switch to command mode and send a command to an already running
 .B haveged
-process or daemon.  Currently the only knows command is
+process or daemon.  Currently the only known commands are
+.I close
+to close the current communication socket of the running
+.B haveged
+process as well as
 .IR root = <new_root>
 where
 .I <new_root>
diff --git a/src/havegecmd.c b/src/havegecmd.c
index 18ff322..0a324ed 100644
--- a/src/havegecmd.c
+++ b/src/havegecmd.c
@@ -26,6 +26,7 @@
 
 #ifndef NO_COMMAND_MODE
 #include <errno.h>
+#include <fcntl.h>
 #include <limits.h>
 #include <stdarg.h>
 #include <stdio.h>
@@ -35,6 +36,7 @@
 #include <sys/ioctl.h>
 #include <sys/types.h>
 #include <sys/socket.h>
+#include <sys/stat.h>
 #include <sys/un.h>
 #include <unistd.h>
 
@@ -49,45 +51,60 @@ struct ucred
 
 #include "havegecmd.h"
 
+int first_byte;
 int socket_fd;
+static char errmsg[1024];
 
-static void new_root(              /* RETURN: nothing                       */
+static int new_root(               /* RETURN: status                        */
    const char *root,               /* IN: path of the new root file system  */
    const volatile char *path,      /* IN: path of the haveged executable    */
    char *const argv[],             /* IN: arguments for the haveged process */
    struct pparams *params)         /* IN: input params                      */
 {
    int ret;
+   struct stat st;
+   const char *realtive = (const char*)&path[0];
 
-   fprintf(stderr, "%s: restart in new root: %s\n", params->daemon, root);
    ret = chdir(root);
    if (ret < 0) {
-      if (errno != ENOENT)
-         error_exit("can't change to working directory : %s", root);
-      else
-         fprintf(stderr, "%s: can't change to working directory : %s\n", params->daemon, root);
+      snprintf(&errmsg[0], sizeof(errmsg)-1,
+               "can't change to working directory %s: %s\n",
+               root, strerror(errno));
+      goto err;
+      }
+   if (path[0] == '/')
+      realtive++;
+   ret = fstatat(AT_FDCWD, realtive, &st, 0);
+   if (ret < 0) {
+      snprintf(&errmsg[0], sizeof(errmsg)-1,
+               "can't restart %s: %s\n",
+               path, strerror(errno));
+      goto err;
       }
    ret = chroot(".");
    if (ret < 0) {
-      if (errno != ENOENT)
-         error_exit("can't change root directory");
-      else
-         fprintf(stderr, "%s: can't change root directory\n", params->daemon);
+      snprintf(&errmsg[0], sizeof(errmsg)-1,
+               "can't change root directory %s\n",
+               strerror(errno));
+      goto err;
       }
    ret = chdir("/");
    if (ret < 0) {
-      if (errno != ENOENT)
-         error_exit("can't change to working directory /");
-      else
-         fprintf(stderr, "%s: can't change to working directory /\n", params->daemon);
+      snprintf(&errmsg[0], sizeof(errmsg)-1,
+               "can't change to working directory / : %s\n",
+               strerror(errno));
+      goto err;
       }
    ret = execv((const char *)path, argv);
    if (ret < 0) {
-      if (errno != ENOENT)
-         error_exit("can't restart %s", path);
-      else
-         fprintf(stderr, "%s: can't restart %s\n", params->daemon, path);
-      }
+      snprintf(&errmsg[0], sizeof(errmsg)-1,
+               "can't restart %s: %s\n",
+               path, strerror(errno));
+   }   
+err:
+   if (ret < 0)
+      print_msg("%s", errmsg);
+   return ret;
 }
 
 /**
@@ -105,7 +122,7 @@ int cmd_listen(                    /* RETURN: UNIX socket file descriptor */
 
    fd = socket(PF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
    if (fd < 0) {
-      fprintf(stderr, "%s: can not open UNIX socket\n", params->daemon);
+      print_msg("%s: can not open UNIX socket\n", params->daemon);
       goto err;
       }
 
@@ -113,7 +130,7 @@ int cmd_listen(                    /* RETURN: UNIX socket file descriptor */
    if (ret < 0) {
       close(fd);
       fd = -1;
-      fprintf(stderr, "%s: can not set option for UNIX socket\n", params->daemon);
+      print_msg("%s: can not set option for UNIX socket\n", params->daemon);
       goto err;
       }
 
@@ -122,7 +139,7 @@ int cmd_listen(                    /* RETURN: UNIX socket file descriptor */
       close(fd);
       fd = -1;
       if (errno != EADDRINUSE)
-         fprintf(stderr, "%s: can not bind a name to UNIX socket\n", params->daemon);
+         print_msg("%s: can not bind a name to UNIX socket\n", params->daemon);
       else
          fd = -2;
       goto err;
@@ -132,7 +149,7 @@ int cmd_listen(                    /* RETURN: UNIX socket file descriptor */
    if (ret < 0) {
       close(fd);
       fd = -1;
-      fprintf(stderr, "%s: can not listen on UNIX socket\n", params->daemon);
+      print_msg("%s: can not listen on UNIX socket\n", params->daemon);
       goto err;
       }
 err:
@@ -154,13 +171,13 @@ int cmd_connect(                   /* RETURN: UNIX socket file descriptor */
 
    fd = socket(PF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
    if (fd < 0) {
-      fprintf(stderr, "%s: can not open UNIX socket\n", params->daemon);
+      print_msg("%s: can not open UNIX socket\n", params->daemon);
       goto err;
       }
 
    ret = setsockopt(fd, SOL_SOCKET, SO_PASSCRED, &one, (socklen_t)sizeof(one));
    if (ret < 0) {
-      fprintf(stderr, "%s: can not set option for UNIX socket\n", params->daemon);
+      print_msg("%s: can not set option for UNIX socket\n", params->daemon);
       close(fd);
       fd = -1;
       goto err;
@@ -169,7 +186,7 @@ int cmd_connect(                   /* RETURN: UNIX socket file descriptor */
    ret = connect(fd, (struct sockaddr *)&su, offsetof(struct sockaddr_un, sun_path) + 1 + strlen(su.sun_path+1));
    if (ret < 0) {
       if (errno != ECONNREFUSED)
-         fprintf(stderr, "%s: can not connect on UNIX socket\n", params->daemon);
+         print_msg("%s: can not connect on UNIX socket\n", params->daemon);
       close(fd);
       fd = -1;
       goto err;
@@ -191,6 +208,7 @@ int getcmd(                        /* RETURN: success or error      */
       const char* opt;
    } cmds[] = {
       { "root=",      MAGIC_CHROOT, 1, NULL },      /* New root */
+      { "close",      MAGIC_CLOSE,  0, NULL },      /* Close socket */
       {0}
    }, *cmd = cmds;
    int ret = -1;
@@ -235,39 +253,52 @@ int socket_handler(                /* RETURN: closed file descriptor        */
    int ret = -1, len;
 
    if (fd < 0) {
-      fprintf(stderr, "%s: no connection jet\n", params->daemon);
+      print_msg("%s: no connection jet\n", params->daemon);
       }
 
    ptr = &magic[0];
    len = sizeof(magic);
    ret = safein(fd, ptr, len);
+   if (ret < 0) {
+      print_msg("%s: can not read from UNIX socket\n", params->daemon);
+      goto out;
+      }
 
-   if (magic[1] == '\002') {       /* read argument provided */
-      unsigned char alen;
+   if (magic[1] == '\002') {       /* ASCII start of text: read argument provided */
+      uint32_t alen;
 
-      ret = safein(fd, &alen, sizeof(unsigned char));
+      ret = receive_uinteger(fd, &alen);
+      if (ret < 0) {
+         print_msg("%s: can not read from UNIX socket\n", params->daemon);
+         goto out;
+         }
 
       optarg = calloc(alen, sizeof(char));
-      if (!optarg)
-          error_exit("can not allocate memory for message from UNIX socket");
-
+      if (!optarg) {
+          print_msg("can not allocate memory for message from UNIX socket");
+          goto out;
+          }
       ptr = (unsigned char*)optarg;
-      len = alen;
-      ret = safein(fd, ptr, len);
+
+      ret = safein(fd, ptr, alen);
+      if (ret < 0) {
+         print_msg("%s: can not read from UNIX socket\n", params->daemon);
+         goto out;
+         }
       }
 
    clen = sizeof(struct ucred);
    ret = getsockopt(fd, SOL_SOCKET, SO_PEERCRED, &cred, &clen);
    if (ret < 0) {
-      fprintf(stderr, "%s: can not get credentials from UNIX socket part1\n", params->daemon);
+      print_msg("%s: can not get credentials from UNIX socket part1\n", params->daemon);
       goto out;
       }
    if (clen != sizeof(struct ucred)) {
-      fprintf(stderr, "%s: can not get credentials from UNIX socket part2\n", params->daemon);
+      print_msg("%s: can not get credentials from UNIX socket part2\n", params->daemon);
       goto out;
       }
    if (cred.uid != 0) {
-      enqry = "\x15";
+      enqry = ASCII_NAK;
 
       ptr = (unsigned char *)enqry;
       len = (int)strlen(enqry)+1;
@@ -276,19 +307,39 @@ int socket_handler(                /* RETURN: closed file descriptor        */
 
    switch (magic[0]) {
       case MAGIC_CHROOT:
-         enqry = "\x6";
+         enqry = ASCII_ACK;
+
+         ret = new_root(optarg, path, argv, params);
+         if (ret < 0) {
+            uint32_t size = strlen(errmsg);
+            safeout(fd, ASCII_STX, strlen(ASCII_STX));
+            send_uinteger(fd, size);
+            safeout(fd, errmsg, size+1);
+            break;
+         }
+
+         ptr = (unsigned char *)enqry;
+         len = (int)strlen(enqry);
+         safeout(fd, ptr, len);
+
+         break;
+      case MAGIC_CLOSE:
+         enqry = ASCII_ACK;
+
+         close(socket_fd);
+         socket_fd = -1;
 
          ptr = (unsigned char *)enqry;
-         len = (int)strlen(enqry)+1;
+         len = (int)strlen(enqry);
          safeout(fd, ptr, len);
+         argv[0][0] = first_byte;
 
-         new_root(optarg, path, argv, params);
          break;
       default:
-         enqry = "\x15";
+         enqry = ASCII_NAK;
 
          ptr = (unsigned char *)enqry;
-         len = (int)strlen(enqry)+1;
+         len = (int)strlen(enqry);
          safeout(fd, ptr, len);
          break;
       }
@@ -308,31 +359,30 @@ out:
 ssize_t safein(                    /* RETURN: read bytes                    */
    int fd,                         /* IN: file descriptor                   */
    void *ptr,                      /* OUT: pointer to buffer                */
-   size_t sz)                      /* IN: size of buffer                    */
+   size_t len)                      /* IN: size of buffer                    */
 {
-   int saveerr = errno, t;
+   int saveerr = errno, avail;
    ssize_t ret = 0;
-   size_t len;
 
-   if (sz > SSIZE_MAX)
-      sz = SSIZE_MAX;
+   if (len > SSIZE_MAX)
+      len = SSIZE_MAX;
 
-   t = 0;
-   if ((ioctl(fd, FIONREAD, &t) < 0) || (t <= 0))
+   ret = ioctl(fd, FIONREAD, &avail);
+   if (ret < 0 || avail <=0)
       goto out;
 
-   len = (size_t)t;
-   if (len > sz)
-      len = sz;
+   if (len > avail)
+      len = avail; 
 
    do {
-      ssize_t p = recv(fd, ptr, len, MSG_DONTWAIT);
+      errno = saveerr;
+      ssize_t p = recv(fd, ptr, len, 0 /* MSG_DONTWAIT */);
       if (p < 0) {
          if (errno == EINTR)
             continue;
          if (errno == EAGAIN || errno == EWOULDBLOCK)
             break;
-         error_exit("Unable to read from socket: %d", socket_fd);
+         print_msg("Unable to read from socket %d: %s", socket_fd, strerror(errno));
          }
       ptr = (char *) ptr + p;
       ret += p;
@@ -340,7 +390,6 @@ ssize_t safein(                    /* RETURN: read bytes                    */
       }
    while (len > 0);
 out:
-   errno = saveerr;
    return ret;
 }
 
@@ -361,7 +410,7 @@ void safeout(                      /* RETURN: nothing                       */
                      continue;
          if (errno == EPIPE || errno == EAGAIN || errno == EWOULDBLOCK)
                      break;
-         error_exit("Unable to write to socket: %d", fd);
+         print_msg("Unable to write to socket %d: %s", fd, strerror(errno));
          }
        ptr = (char *) ptr + p;
        len -= p;
@@ -371,4 +420,41 @@ void safeout(                      /* RETURN: nothing                       */
    errno = saveerr;
 }
 
+/**
+ * Send outgoing unsigned integer to socket
+ */
+void send_uinteger(                /* RETURN: nothing                       */
+   int fd,                         /* IN: file descriptor                   */
+   uint32_t value)                 /* IN: 32 bit unsigned integer           */
+{
+   uint8_t buffer[4];
+
+   buffer[0] = (uint8_t)((value >> 24) & 0xFF);
+   buffer[1] = (uint8_t)((value >> 16) & 0xFF);
+   buffer[2] = (uint8_t)((value >>  8) & 0xFF);
+   buffer[3] = (uint8_t)((value >>  0) & 0xFF);
+
+   safeout(fd, buffer, 4 * sizeof(uint8_t));
+}
+
+/**
+ * Receive incomming unsigned integer from socket
+ */
+int receive_uinteger(              /* RETURN: status                        */
+   int fd,                         /* IN: file descriptor                   */
+   uint32_t *value)                /* OUT: 32 bit unsigned integer          */
+{
+   uint8_t buffer[4];
+
+   if (safein(fd, buffer, 4 * sizeof(uint8_t)) < 0)
+      return -1;
+
+   *value = (((uint32_t)buffer[0]) << 24) |
+            (((uint32_t)buffer[1]) << 16) |
+            (((uint32_t)buffer[2]) <<  8) |
+            (((uint32_t)buffer[3]) <<  0);
+
+   return 0;
+}
+
 #endif
diff --git a/src/havegecmd.h b/src/havegecmd.h
index 997c5d1..a9f2b9a 100644
--- a/src/havegecmd.h
+++ b/src/havegecmd.h
@@ -34,6 +34,12 @@ extern "C" {
 
 #define HAVEGED_SOCKET_PATH      "\0/sys/entropy/haveged"
 #define MAGIC_CHROOT             'R'
+#define MAGIC_CLOSE              'X'
+#define MAGIC_PATH               'P'
+
+#define ASCII_ACK                "\x6"    /* ASCII acknowledge */
+#define ASCII_NAK                "\x15"   /* ASCII negative acknowledge */
+#define ASCII_STX                "\x2"    /* ASCII start of text */
   
 #ifndef SOCK_CLOEXEC
 #define SOCK_CLOEXEC 0
@@ -74,10 +80,21 @@ ssize_t safein(int, void *, size_t);
 void safeout(int, const void *, size_t);
 
 /**
+ * Send outgoing unsigned integer to socket
+ */
+void send_uinteger(int, uint32_t);
+
+/**
+ * Receive incomming unsigned integer from socket
+ */
+int receive_uinteger(int, uint32_t *);
+
+/**
  * Socket file descriptor used for communication
  */
 
 extern int socket_fd;
+extern int first_byte;
 
 #ifdef __cplusplus
 }
diff --git a/src/haveged.c b/src/haveged.c
index 733d0da..4440a45 100644
--- a/src/haveged.c
+++ b/src/haveged.c
@@ -19,6 +19,7 @@
  ** along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 #include "config.h"
+#include <sys/auxv.h>
 #include <stdlib.h>
 #include <stdio.h>
 #include <getopt.h>
@@ -118,7 +119,6 @@ static void set_watermark(int level);
 static void anchor_info(H_PTR h);
 static int  get_runsize(unsigned int *bufct, unsigned int *bufrem, char *bp);
 static char *ppSize(char *buffer, double sz);
-static void print_msg(const char *format, ...);
 
 static void run_app(H_PTR handle, H_UINT bufct, H_UINT bufres);
 static void show_meterInfo(H_UINT id, H_UINT event);
@@ -135,6 +135,8 @@ int main(int argc, char **argv)
 {
    volatile char *path = strdup(argv[0]);
    volatile char *arg0 = argv[0];
+   if (path[0] != '/')
+      path = (char*)getauxval(AT_EXECFN);
    static const char* cmds[] = {
       "b", "buffer",      "1", SETTINGR("Buffer size [KW], default: ",COLLECT_BUFSIZE),
       "d", "data",        "1", SETTINGR("Data cache size [KB], with fallback to: ", GENERIC_DCACHE ),
@@ -188,6 +190,7 @@ int main(int argc, char **argv)
    params->setup |= MULTI_CORE;
 #endif
 
+   first_byte = arg0[0];       
    if (access("/etc/initrd-release", F_OK) >= 0) {
       arg0[0] = '@';
       path[0] = '/';
@@ -339,8 +342,10 @@ int main(int argc, char **argv)
 #ifndef NO_COMMAND_MODE
    if (params->setup & CMD_MODE) {
       int ret = 0, len;
-      char *ptr, message[PATH_MAX+5], answer[2], cmd[2];
+      uint32_t size;
+      char *ptr, answer[6], cmd[2];
       fd_set read_fd;
+      sigset_t block;
 
       socket_fd = cmd_connect(params);
       if (socket_fd < 0) {
@@ -357,14 +362,15 @@ int main(int argc, char **argv)
          char *root;
          case MAGIC_CHROOT:
             root = optarg;
-            len = (int)strlen(root);
-            ret = snprintf(message, sizeof(message), "%c\002%c%s%n", cmd[0], (int)(strlen(root) + 1), root, &len);
-            if (ret < 0 || (unsigned) ret >= sizeof(message)) {
-               fprintf(stderr, "%s: can not store message\n", params->daemon);
-               break;
-            }
-            ptr = &message[0];
-            len += 1;
+            size = (uint32_t)strlen(root)+1;
+            cmd[1] = '\002';
+            safeout(socket_fd, &cmd[0], 2);
+            send_uinteger(socket_fd, size);
+            safeout(socket_fd, root, size);
+            break;
+         case MAGIC_CLOSE:
+            ptr = &cmd[0];
+            len = (int)strlen(cmd)+1;
             safeout(socket_fd, ptr, len);
             break;
          case '?':
@@ -374,13 +380,15 @@ int main(int argc, char **argv)
          }
       answer[0] = '\0';
       ptr = &answer[0];
-      len = sizeof(answer);
+
+      sigemptyset(&block);
+      sigaddset(&block, SIGPIPE);
 
       FD_ZERO(&read_fd);
       FD_SET(socket_fd, &read_fd);
 
       do {
-         struct timeval two = {2, 0};
+         struct timeval two = {6, 0};
          ret = select(socket_fd+1, &read_fd, NULL, NULL, &two);
          if (ret >= 0) break;
          if (errno != EINTR)
@@ -388,15 +396,37 @@ int main(int argc, char **argv)
          }
       while (1);
 
-      ret = safein(socket_fd, ptr, len);
-      close(socket_fd);
+      ret = safein(socket_fd, ptr, 1);
       if (ret < 0)
          goto err;
-      if (answer[0] != '\x6')
-         ret = -1;
-      else
-         ret = 0;
+      switch (answer[0]) {
+         case '\002': {
+               char *msg;
+               ret = receive_uinteger(socket_fd, &size);
+               if (ret < 0)
+                  goto err;		   
+               msg = calloc(size, sizeof(char));
+               if (!msg)
+                  error_exit("can not allocate memory for message from UNIX socket: %s",
+                              strerror(errno));
+               ret = safein(socket_fd, msg, size);
+               if (ret < 0)
+                  goto err;
+               fprintf(stderr, "%s: %s", params->daemon, msg);
+               free(msg);
+               ret = -1;
+            }
+            break;
+         case '\x6':
+            ret = 0;
+            break;
+         case '\x15':
+         default:
+            ret = -1;
+            break;
+         }
    err:
+      close(socket_fd);
       return ret;
       }
    else {
@@ -404,13 +434,13 @@ int main(int argc, char **argv)
       if (socket_fd >= 0)
          fprintf(stderr, "%s: command socket is listening at fd %d\n", params->daemon, socket_fd);
       else {
-        if (socket_fd == -2) {
-	        fprintf(stderr, "%s: command socket already in use\n", params->daemon);
-	        fprintf(stderr, "%s: please check if there is another instance of haveged running\n", params->daemon);
-	        fprintf(stderr, "%s: disabling command mode for this instance\n", params->daemon);
-        } else {
-	        fprintf(stderr, "%s: can not initialize command socket: %s\n", params->daemon, strerror(errno));
-        }
+         if (socket_fd == -2) {
+            fprintf(stderr, "%s: command socket already in use\n", params->daemon);
+            error_exit("%s: please check if there is another instance of haveged running\n", params->daemon);
+         } else {
+            fprintf(stderr, "%s: can not initialize command socket: %s\n", params->daemon, strerror(errno));
+            fprintf(stderr, "%s: disabling command mode for this instance\n", params->daemon);
+         }
       }
     }
 #endif
@@ -834,7 +864,7 @@ static char *ppSize(       /* RETURN: the formatted size */
 /**
  * Execution notices - to stderr or syslog
  */
-static void print_msg(     /* RETURN: nothing   */
+void print_msg(            /* RETURN: nothing   */
    const char *format,     /* IN: format string */
    ...)                    /* IN: args          */
 {
diff --git a/src/haveged.h b/src/haveged.h
index 9b1efaf..40e07a0 100644
--- a/src/haveged.h
+++ b/src/haveged.h
@@ -92,4 +92,9 @@ typedef struct {
   */
 void error_exit(const char *, ...);
 
+/**
+  * Execution notices - to stderr or syslog
+  */
+void print_msg(const char *, ...);
+
 #endif